On January 5, the national average for on-highway diesel was $3.477 a gallon. On November 9 it was $6.127. That’s $2.65 a gallon in ten months, a 76% increase, on the single largest variable cost in moving a truck.
Put it in miles. At 6.5 miles per gallon, that change adds about 41 cents of fuel to every mile. A 1,000-mile load that burned roughly $535 of diesel in January burns about $943 today. Same truck, same lane, same freight.
Most shippers know fuel is up. Fewer know which number to plan against. That’s where the budget goes wrong.
Crude is the headline. Diesel is the bill.
The run-up started with the conflict that began on February 28 and the disruption that followed to Middle East production and to shipping through the Strait of Hormuz. Diesel reacted immediately: the national average jumped 96 cents in a single week, from $3.897 on March 2 to $4.859 on March 9. It peaked at $6.529 the week of September 21.
Here is the part that matters for planning. Brent crude averaged $124 a barrel in October, then dropped below $100 on November 4, a fall of roughly a fifth. Over nearly the same stretch, diesel moved from $6.352 to $6.127. That’s 3.5%.
Crude fell hard. Diesel barely noticed.
The gap between the two is the refining margin, and this year it is doing as much work as the barrel. The U.S. Energy Information Administration attributes it to damaged refining capacity in the Middle East and Russia cutting the supply of finished fuel, and it expects that margin to stay wide through most of 2027. A truck doesn’t burn crude. It burns a refined product with its own supply chain and its own bottlenecks.
So when the news says oil is coming down, the right question is what diesel did. It’s a different answer more often than people expect.
What the forecast says, and how much to trust it
EIA’s November outlook has diesel easing from here, slowly:
| Period | EIA forecast, U.S. retail diesel |
|---|---|
| Q4 2026 | $6.05 |
| Q1 2027 | $5.37 |
| Q2 2027 | $5.03 |
| Q3 2027 | $4.91 |
| Q4 2027 | $4.80 |
| 2027 average | $5.03 |
Two things to take from that table. First, even the low end of 2027 sits more than a dollar above where this year started. EIA’s outlook never gets back near $3.50.
Second, that $5.03 average was $4.49 one month earlier. The forecast moved 54 cents in thirty days, and EIA says plainly that Middle East crude flows remain open to disruption and that a hard winter or an unplanned refinery outage could push prices higher than its monthly numbers show.
A forecast that moves 12% in a month is not a number to build a budget on. It’s a range.
Know how your fuel surcharge is actually built
Most truckload fuel surcharges follow the same arithmetic: take a published diesel index, subtract a base price, divide by an agreed miles-per-gallon figure. The result is cents per mile, reset weekly when the index publishes.
Three terms decide what you pay, and all three are in your contracts right now:
The index. National average or regional? On November 9, California diesel was $7.897 and the Gulf Coast was $5.741. That’s a $2.16 spread on the same day. If your freight runs in one region and your surcharge is pegged to another, you’re either overpaying or about to have a hard conversation with a carrier who is underwater.
The base. The price at which the surcharge is zero. A low base puts more of the fuel cost in the surcharge, where you can see it. A high base buries it in the linehaul rate.
The miles-per-gallon divisor. A table written at 6 mpg charges about 8% more per mile than one written at 6.5 for the same fuel price. It’s rarely revisited, and it compounds on every load.
Then there are all-in rates, where fuel is folded into one number. They feel simpler. They also make it impossible to tell whether a rate went up because the market tightened or because diesel moved, which means you can’t tell whether it should come back down.
Budget in scenarios, and work the part you control
Fuel is roughly a fifth of what it costs to run a truck. The American Transportation Research Institute put it at about 48 cents of a $2.34 per-mile operating cost in 2025, when diesel was far cheaper than it is today. That share has almost certainly grown since.
For 2027, carry three fuel lines instead of one. Using EIA’s range and the same 6.5 mpg:
| Diesel price | Fuel per mile | Fuel per 1,000 miles |
|---|---|---|
| $4.80 (EIA’s late-2027 low) | $0.74 | $738 |
| $5.37 (EIA’s Q1 2027) | $0.83 | $826 |
| $6.13 (today) | $0.94 | $943 |
Multiply by your annual miles and you have the spread your budget needs to survive. Keep fuel as its own line, separate from linehaul, so that when the number moves you can explain it in one sentence.
Then work on what’s actually yours. Nobody negotiates the price of a barrel. What a shipper controls is how many miles the freight travels and how many trucks it takes to get there:
- Fewer, fuller trucks. Every load you eliminate saves 100% of its fuel, at any price. Consolidation is worth more at $6 diesel than it was at $3.50.
- Mode. Rail intermodal moves freight on a fraction of the fuel a truck uses per ton. Lanes that didn’t pencil in January may pencil now.
- Empty and out-of-route miles. They carry a full fuel bill and no freight.
- The surcharge terms themselves. Index, base, and divisor are all negotiable, and most haven’t been looked at since they were signed.
This is the work HOP Logistics does alongside customers ahead of budget season: fuel isolated from linehaul in the reporting, surcharge schedules checked against where the freight actually runs, and the network engineered to take miles out before anyone talks about rates.
You can’t plan the barrel. You can plan the miles.
Diesel prices are from the U.S. Energy Information Administration’s weekly on-highway survey through November 9, 2026. Forecasts are from EIA’s November 2026 Short-Term Energy Outlook; they are EIA’s, not HOP’s, and they are revised every month. Operating-cost figures are from the American Transportation Research Institute’s 2026 report on 2025 costs. Per-mile figures assume 6.5 miles per gallon for illustration.